Not too bad, but it would be best to find a donor car with the parts. You need the window regulators, the wiring harnesses in the doors, the harness under the dash from door to door, a circuit breaker for the fuse box, and I would recommend aftermarket lock actuators instead of Ford unless you get them really cheap. Of course you will need new door panels and armrests with the switches included. I put them in my stripped LX several years ago. The power to the harness is supplied froma plug under the drivers kick panel and it just plugs right in. Not too hard, but it is a chore to obtain all the wiring and parts. Also, the wiring on the switches and doors changed a bit in 92 or so, another reason to get it all from one car.
Good luck!